Dry cell



March 28, 1939. KELLER 2,152,433

DRY CELL Filed Dec. 21, 1935 INVENTOR.

%RNEYS Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE DRY CELL Application December 21, 1935, Serial No. 55,550

3 Claims.

This invention relates to a dry cell which may be made so as to have a metal cup or casing as one electrode or terminal and a rod of conducting material, such as carbon, for example, constituting the other electrode or terminal.

It is well known that with dry cells of this character there is danger of the cells becoming short circuited by a piece of conducting material becoming inadvertently placed in contact with the center contacting pole and the rim or edge of the metal cup or casing. By the present invention the danger of short circuits being inadvertently caused in this way, by other cells or other pieces of contacting material having substantially straight or slightly curved edges, is avoided.

The invention will be understood from the description in connection with the accompanying drawing, in which Fig. 1 is a side view partly in vertical section through an illustrative embodiment of the invention and Fig. 2, is an end view of the same.

In the drawing, reference character I indicates a casing that is made of metal, such as zinc, for

example. The casing may have a sleeve 2 of insulating material therearound as shown in dotted lines. The upper end 3 of the positive pole, which may be made of a carbon rod, for example, is shown in section. The upper surface of the sealing wax. or the like, which prevents the electrolyte from escaping, is indicated by the refer ence character 4. A metal cap 5 is pressed upon the upper end of the electrode 3 in the usual way to form the positive terminal. This cap has an outwardly extending flange G. A disc 1 of insulating material is provided with a central hole 8 that fits the cap 5 and this disc rests upon the flange 6.

A metal ring 9 has an opening l0 therethrough which is large enough to leave an annular space I l around the cap 5 when the ring 9 is in place. The annular downwardly extending flange i2 of the ring 9 which defines the outer periphery of the opening ID has its edge resting upon the upper surface of the disc I. The diameter of the flange 6 of the cap 5 is preferably slightly larger than the diameter of the annular flange ll of the ring 9.

The outer annular flange l3 of the ring 9 extends downwardly below the disc and the inside surface of this flange fits the outer periphery of this disc.

The flange I3 terminates in an outwardly extending horizontally disposed annular lip M.

The washer i5, of stiff insulating material, having an opening large enough to accommodate the main portion of the ring 9, rests upon the lip l4 and its outer periphery fits in the inside of the casing I.

An internal annular rib I6 is pressed in the casing I below the washer l5 and the upper edge of the casing l is rolled over onto the upper side of this washer l5, as indicated at IT.

The upstanding annular portion of the ring 9 is sufficiently high to prevent electrical connection being made between the rim ll and cap 5 by a straight piece of conducting material, as this portion of the ring 9 will operate as a fulcrum to prevent such a piece of conducting material from simultaneously touching the rim l1 and cap 5 and thus short circuiting the cell. The ring 9 may be made of metal or other stiff or rigid material that has enough strength to serve the purpose.

The ring 9 cannot shift laterally as its flange I3 fits around the edge of the disc I and the opening 8 in this disc flts the cap 5, which, in turn, is frictionally pressed upon the end of the rod 3.

I claim:

1. In a dry cell, a metal casing forming one electrode, a rod of conducting material in said casing, a metal cap on said rod having an outwardly extending flange, a flat washer oi insulating material on the top side of said flange, and an annular metallic member on said washer extending above straight lines from said cap to the end of said casing and having a flange along its outer edge and inside of said casing, the inner side of said flange contacting with the outer edge of said flat washer, and a washer of insulating material held between said last named flange and said casing with its inner edge contacting with the outer side of said flange.

2. In a dry cell, a metal casing forming one electrode, a rod of conducting material in said casing forming the other electrode, a metal cap on the end of said rod having a flange, a washer of insulating material supported on said flange, an annular metal member having two flanges of different lengths, the shorter one of which rests upon the upper surface of said washer and the longer one has an out-turned lip, and a larger washer supported by said lip and the upper end of said casing.

3. In a dry cell, a casing, a flanged cap at the end of the center contact of said cell, a plurality of annular members consisting of two insulating members and an intermediate metal member of successively larger outside diameters and inside diameters having the inside diameter of each smaller than the outside diameter of the precedsaid metal member extending above straight lines from said cap to the upper end of said casing and 'having a downwardly and outwardly extending portion between said insulating members and contacting with the edges thereof.

FREDERICK A. KELLER. 

